Yes, healthy. It's natural to be nervous before you speak. Seasoned actors suffer from stage fright now and then and may even forget their lines. TV anchors feel nervous before they go on the air. And even the best speakers have moments in which they wish they were anywhere doing anything.
The difference between nervousness and fear is that fear is debilitating, but nervousness is controllable. It's also useful. It keeps you from being overconfident.
If nervousness seems to be a problem, it's a far less serious one than overconfidence. Dr. Kenneth McFarland, who was once voted Number One Public Speaker in America by the U.S. Chamber of Commerce, relates this anecdote in his book, Eloquence in Public Speaking:
I was recently ...